// Copyright 2008, 2009 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.corelib.base;

 import org.apache.tapestry5.BindingConstants;

 import org.apache.tapestry5.Link;

 import org.apache.tapestry5.MarkupConstants;

 import org.apache.tapestry5.MarkupWriter;

 import org.apache.tapestry5.annotations.Environmental;

 import org.apache.tapestry5.annotations.Parameter;

 import org.apache.tapestry5.ioc.annotations.Inject;

 import org.apache.tapestry5.services.ClientBehaviorSupport;

 import org.apache.tapestry5.services.Request;

 /**

  * Base class for link-generating components that are based on a component event request. Such events have an event

  * context and may also update a {@link org.apache.tapestry5.corelib.components.Zone}.

  */

 public abstract class AbstractComponentEventLink extends AbstractLink

 {

     /**

      * The context for the link (optional parameter). This list of values will be converted into strings and included in

      * the URI. The strings will be coerced back to whatever their values are and made available to event handler

      * methods.

      */

     @Parameter

     private Object[] context;

     /**

      * Binding the zone parameter turns the link into a an Ajax control that causes the related zone to be updated.

      */

     @Parameter(defaultPrefix = BindingConstants.LITERAL)

     private String zone;

     @Environmental

     private ClientBehaviorSupport clientBehaviorSupport;

     @Inject

     private Request request;

     void beginRender(MarkupWriter writer)

     {

         if (isDisabled()) return;

         Link link = createLink(context);

         writeLink(writer, link);

         if (zone != null)

         {

             if (!request.isXHR())

                 writer.getElement().forceAttributes(MarkupConstants.ONCLICK, MarkupConstants.WAIT_FOR_PAGE);

             clientBehaviorSupport.linkZone(getClientId(), zone, link);

         }

     }

     /**

      * Invoked to create the Link that will become the href attribute of the output.

      *

      * @param eventContext the context as an object array, possibly null

      */

     protected abstract Link createLink(Object[] eventContext);

     void afterRender(MarkupWriter writer)

     {

         if (isDisabled()) return;

         writer.end(); // <a>

     }

 }